A 63 years old caucasian woman with large grouped hemorrhagic papules and nodules in her extremities.


    Clinical findings; A 63 years old Caucasian woman presented with large grouped hemorrhagic papules in the left thigh one year ago. She also had several erythematous macules and patches in the lower and upper extremities. She first recognized a few early erythematous macules, which grew in size and increased in the number. One year ago, two excisional biopsies were performed, but inconclusive. All these previous slides had been received and reviewed. Morphological features are same as those found in the current biopsy from the left thigh lesion, confirming the diagnosis of Rosai-Dorfman disease (RSD). One year ago, physical examination, peripheral blood test and chest X-ray were negative. In the current visit, there were no lymphadenopathy and oral mucosa lesions detected. She had been referred to a hemato-oncologist and extensive clinical work-up was scheduled.

    Pathologic findings; Histological sections showed dense mixed cellular infiltrate, alternating sheets of dark and light infiltrates, throughout the dermis and subcutis. The epidermis and adnexal structures were spared. The infiltrates were composed of sheets of atypical histiocytes admixed with dense plasma cells and lymphocytes. Rare eosinophils were noted. The tumor cells showed plump clear cytoplasm with vesicular nuclei and small conspicuous nucleoli. Features of emperipolesis were also observed. Scattered lymphoid follicles with germinal centers were present in the deep infiltrate. Immunohistochemical studies showed that the tumor cells were intensely positive for S100 and weakly but diffusely positive for CD68. Immunophenotype also supported the diagnosis of RSD.